Cyclonic combustion burner

ABSTRACT

A compact cyclonic burner having a tangential fuel input and peripheral secondary air inlets arranged in such a manner that the secondary air combines more readily with the liquid or gaseous burning fuel during the combustion process by aiding the vaporizing, distilling, gasifying and oxidizing of the burning fuel.

United States Patent 1191 Robbins CYCLONIC COMBUSTION BURNER [76]Inventor: Donald D. Robbins, 3539 E. 1

I Piccadilly Rd., Phoenix, Ariz. 85018 22 Filed: 061. 10, 1972 21 Appl.No.2 296,308

[52] US. Cl. 431/158, 431/173, 431/351 [51] Int. Cl. F23! l/00 [58]Field of Search 431/173, 351, 353, 157,

[56] References Cited I UNITED STATES PATENTS 3,667,221 6/1972 Taylor431/173 [-451 Apr. 16, 1974 3,437,085 4/1969 Perry 431/173 FOREIGNPATENTS OR APPLICATIONS 1,004,670 11/1951 France 431/173 PrimaryExaminer-Carroll B. Dority, Jr. Attorney, Agent, or Firm-Warren F.BLLindsley [5 7] ABSTRACT A compact cyclonic burner having a tangentialfuel input and peripheral secondary air inlets arranged in such a mannerthat the secondary air combines more readily with the liquid or gaseousburning fuel during the combustion process by aiding the vaporizing, distilling, gasifying and oxidizing of the burning fuel.

' 5 Claims, 5 Drawing Figures PATENTED R 6mm 4 3.804.578

SHEH 1 OF 2 CYCLONIC COMBUSTION BURNER BACKGROUND OF THE INVENTIONHeretofore burners for furnaces, boilers, water heaters and the likehave been relatively complicated in construction and have employednumerous parts in their manufacture, which makes them subject to a lotof maintenance, and they require skilled craftsmen to install and adjustthem in order to obtain a degree of efficiency in operation.

The preliminary requirement in using any form of fuel is its conversioninto a gas in order that it may combine more readily with oxygen in thecombustion process. In most fuels, the chief combustible elements arecarbon (C) and hydrogen (H), which are present in a great variety ofchemical combinations with varying physical characteristics. When thesefuels are completely burned, the products of combustion contain onlycarbonic acid, namely carbon dioxide (CO and water (H O), with nitrogen(N) and some of the oxygen of the air supplied for combustion, all ofwhich are incombustible. But'when the fuel is incompletely or partiallyburned, the products of combustion will also contain varying quantitiesof carbon monoxide (CO), various forms of hydrocarbon (C H hydrogen andsometimes tar and smoke as the products of distillation, all of whichare combustible or have a heating value, which is wasted if not oxidizedin the combustion process.

Fuel may be burned by eitherdirect firing on a grate or after conversioninto gaseous form. The ultimate object of direct firing is theattainment of complete combustion in close proximity to the fuel bed byvaporizing, distilling, gasifying and completely burning the fuel withinthe same chamber. It is well known, however, that the processes ofvaporization and distillation do not produce heat but, on the contrary,absorb it, and therefore it is advantageous to separate them from thepoint at which the combustion of the gases takes place and where hightemperatures are developed by the heat evolved, as is accomplished bythe use of a gas producer or generator.

In the gas producer or generator, the process of vaporization,distillatioriand gasification results in the generation of combustiblegas, which is led away to a separate combustion chamber in which it issubsequently burned under conditions more favorable to a fullrealization of the heat value of the fuel.

FIELD OF THE INVENTION This invention relates to a simple,compactcyclonic burner employing a new and improved gas generator whichis easy to install and adjust and which will provide a highly efficientburning of the fuel used. In addition, the present invention provides aburner which can be set at anyangle to direct the heat to any desireddirection, that is, up, down, to either or both sides, and even atangles, should this be desired, without destroying the effectiveness ofthe gas generator. Also, the present invention is designed to burngaseous and liquid fuels more efficiently to provide more heat morequickly with less BTU input than conventional burners by burning thenormal products of incomplete combustion, since the burner operates at ahigher temperature than heretofore possible.

DESCRIPTION OF THE PRIOR ART It is well known that present burners forfurnaces, boilers, water heaters, and the like are complicated andtouchy to install and adjust for efficient operation. The complicatedconstruction of the burners results in a higher cost of manufacture, andtherefore the selling price is relatively high. The complicatedconstruction also makes these burners more expensive to maintain and toadjust, even though they can never by an efficient burner of fuels. Attheir best they still produce combustable carbon monoxide. Thus, it isdesirable to produce a gas generator which will provide a timely andproper amount of secondary air so as to convert the carbon monoxide intoincomb'ustable carbon dioxide, thereby obtaining complete combustion ofthe fuel used.

SUMMARY OF THE INVENTION In accordance with the invention claimed, thecyclonic burner disclosed embodies a gas generator of the simplestpossible construction and can be manufactured at a relatively low costbut still obtain complete combustion of the burner fuel used. Inaddition, this invention provides a burner which will burn liquid orgaseous fuels at a higher temperature than the prior art burners,thereby burning the heretofore unburned combustible elements. I

It is, therefore, one object of this invention to provide a cyclonicburner for liquid and/ or gaseous fuels employing a new gas generatorwhich is compact and of simple construction. i i

Another object of this invention is to provide a new and improved burnerwhich effectively converts carbonaceous fuel into carbon monoxide gasand then burns it completely.

A further object of this invention is to provide a burner which, bymeans of secondary air introduced in a given manner, efficiently andcleanly burns the fuel at higher temperatures. 1 e

A still further object of this invention is to provide a burner whichmay be installed at any angle to direct heat in any one or more desireddirections.

A still further object of this invention is to provide a .burner whichmay havemore than one fuel input associated therewith so that the burnermay be utilized with more than one kind of fuel, whereby either or bothfuels may be used in the burner as desired."

A still further object of this invention is to provide a simple, compactburner with tangentially disposed fuel inlets, thereby causing the fueltotraverse a cyclonic path during initial and final burning of the fuel.

A still further object of this invention is to provide a simple, compactburner which has a substantially circular burner housing to provide forthe cylonic burning of fuels in conjunction with the tangential fuelinput.

A still further object of this invention is to provide a plurality ofsecondary air inlets or slots around the periphery of the burner housingthrough which preheated secondary air will be drawn to aid in theburning of heavier fuel particles. l i

A still further object of this invention is to provide an interiorbafflewithin the burner to control the movement of and direct burning fuelinto the path of the incoming fuel-air mixture to ensure proper ignitionand burning of the fuel.

A specific object of this invention is to provide a high speed cyclonicor rotary path of the burning fuels whereby the heavier particles of thefuel will be carried near the outside of the burning gases near thesecondary air inlets so that secondary air will be drawn into the burnerto implement the complete burning of the heavier fuel particles toprovide the highest possible efficiency of fuel burning the BTUrecovery, and minimize, if not preclude, the discharge of undesirableunburned fuels from the burner.

A further specific object of this invention is to provide a burner witha plurality of fuel inlets whereby low-fire and high-fire conditions maybe easily attained, still maintaining efficient burner operation.

These and other objects and advantages of the present invention willbecome more apparent as the description proceeds, and the features ofnovelty which characterize this invention will be pointed out withparticularity in the claims annexed to and forming part of thisspecification.

BRIEF DESCRIPTION OF THE DRAWING The present invention may be morereadily described by reference to the accompanying drawings, in which:

FIG. 1 is a perspective view, with parts broken away, of a cyclonicburner employing the invention.

FIG. 2 is'a sectional view on the line 2-2 of FIG. 1 but showing aventuri-type fuel-air input tube.

FIG. 3 is-a view similar to FIG. 1 but illustrating a burner with twofuel inputs, one a gaseous fuel input, and the other a liquid fuelinput.

FIG. 4 is a horizontal sectional view of a modified form of my cyclonicburner which has a secondary air housing surrounding the burner housingto supply secondary air from an external source.

FIG. 5 is a perspective view of a modified form of my cyclonic burner,with parts broken away, showing more than one fuel-air inlet.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring more particularly tothe drawings by characters of reference, FIG. 1 and 2 illustrate aburner comprising a housing 1 substantially circular in shape and havingtwo spaced opposed sides 2 and 3, which for convenience in descriptionwill be called the top and bottom, respectively, of the burner. Althoughshown in a horizontal position, it is to be understood that thedisposition of the burner may be at any desired angle or position toserve a particular need. The top and bottom of the burner are joined bysubstantially perpendicular side walls 4, which form the periphery ofthe burner.

Housing 1 is preferably fabricated from any suitable high heat resistantmaterial, for example, stainless steel, or it may be made with asuitable material having a ceramic lining or coating.

A fuel and air intake 5 is connected to housing 1 and is disposed so asto provide a tangential extension of the side wall 4, as shown. Theintake 5 preferably includes a tubular extension into which fuel,indicated by arrows 6-6, may be injected into housing 1 of the burner byfuel nozzle 7. The fuel injected into input 5 draws air with it intohousing 1 through input 5 and the fuel and air then pass over anignition device 8. The ignition device 8 is located within the burnerhousing adjacent intake 5. The fuel is ignited and caused to swirlaround the inside of the housing as it burns in a cyclonic action.

As seen in the drawing, top 2 of the housing is provided with a circularperforated exhaust plate 9 axially mounted thereon to provide theexhaust or discharge of the burner. Heat from the burner will beconcentrated and transmitted through exhaust plate 9 and may be directedin any suitable direction by suitably mounting the burner. Althoughexhaust plate 9 is shown and described, it should be noted that it maybe omitted and the burner would function satisfactorily.

The cyclonicburning action and its centrifugal characteristics causesthe heavier and larger fuel particles to be carried in suspension in theburning gases adjacent the periphery of the burner, that is, adjacentwalls 4; while the smaller and lighter fuel particles tend to movetoward the center of the cyclonic movement and are burned more readilyand quickly.

To ensure complete burning of the larger, heavier fuel particles as theyare swirled in the burner housing as well as maintaining the burningbases longer in the burning housing,.a gas generator is provided aroundthe inside periphery of housing 12 which includes a plurality ofsecondary air inlets 1010 through the peripheral walls 4. Secondary airwill be drawn into the burner housing through these air inlets bysuction action created by the swirling burning gases in housing 1. Thisswirling action aids the combustion of the fuel carried adjacent theouter periphery of the burner housing by oxidizing the unburned gases.It is deemed apparent that the air drawn into the housing through thesecondary air inlets will be preheated by the inherent heat of thehousing while the burner is operating, and that this preheated air willassist the burning of the larger and heavier fuel particles, which asthey burn will become lighter and therefore will move inwardly towardthe center of the cyclonic burning gases and should be completelyconsumed by the time they are exhausted through the discharge 9. Sinceit is necessary to vaporize, distill, and gasify the fuel beforecomplete combustion occurs, and since it is desirable to separate thisaction from the zone of complete combustion, the area around the insideperiphery of the housing which is partly closed by sides 2, 3 and 4performs this function. It is, in fact, a generating area for the centerof the burner and furnishes fuel to the centerof the cyclonic burner forburning without. the center of the burner being cooled by thevaporizing, distilling, gasification and oxidation action.

As may be more clearly seen in the sectional view of FIG. 4, thesecondary air inlets 10-10 have a lip 11 which extends into the burnerchamber 12 so that there is an overlap to create a pressure drop orsuctionto aid in drawing or pulling of secondary air into the burnerchamber, and to preclude any blow-back through the secondary air inlets.

OPERATION In the operation of the burner, shown in FIG. 1, liquid orgaseous fuel 6 such as propane gas is injected into the combustion orburner chamber 12 from nozzle 7 through the tubular air and fuel intake5. The fuel injection process draws primary air into intake 5, as wellknown in the art, and air and fuel 6 enters the combustion chamber 12after passing over the ingition device 8. Device 8 may be of any desiredtype, such as, for example, a spark device or pilot flame 13, as shownin FIG. 5. The fuel is ignited and starts to swirl around the inside ofthe periphery of chamber 12 in a zone identified as a gas generator in acyclonic action to vaporize, distill and fully gasify thefuel and air sothat the complete high temperature burning of the gases may occur in thecenter portion of the burner.

In FIG. 4 is shown an arcuate baffle or deflector plate 14 which isinstalled within the burner chamber in spaced relationship to the outeror peripheral walls 4, the arc of the plate corresponding to the arcuateshape of the adjacent walls whereby a narrow passage 15 is providedbetween the outer walls 4 and the center portion of the burning chamber12. The baffle 14 serves to ensure that some of the burning gases of thecyclonic burning mixture are maintained adjacent the outer walls 4 inthe gas generator portion of the burner until the gas is completelyvaporized, distilled and gasified and directed across the tangentialfuel inlet 5 so that the ignition of newly injected fuel is positivelyensured.

MODIFICATIONS In FIG.2 a sectional view of the fuel inlet 5 is shownwherein opening.16 is of a venturi shape to assist in drawing air andfuel into the burner chamber.

In addition, FIG. 2 shows an auxiliary fuel supply line 17 mounted inthe fuel intake 5, whereby a second fuel such as No. 2 fuel oil 18 maybe introduced from a fuel source or supply not shown. The venturi actioncreated by the venturi inlet 16 will draw the fuel, for example, fueloil, into the burner chamber 12 for burning. It is deemed apparent thatthe propane fuel and/or the fuel oil can be burned either singly ortogether to obtain a desired result. All other parts of the burner aresimilar to those shown in FIG. 1 and given the same referencecharacters. Like parts in FIGS. 2-5 also have similar referencecharacters. 1

In FIG. 3 a dual fuel feed system is shown for the burner. One feedstructure comprises the propane or gaseous fuel nozzle 7 heretoforedescribed feeding into a fuel intake 5. Disposed at about 180? therefromis a second fuel inlet 5A. The second fuel inlet SA has a fueloilinjection nozzle 19 and an ignition device 8. Fuel intake 5 also has anignition device, not shown. The two fuel inlets! and 5A may be usedsingly or together to meet fuel availability or heat requirements, andbecause the inlets are tangentially arranged relative toburner chamber12, they will each provide for an assist in obtaining the cyclonicburning action. It should be recognized that both fuel inlets maydischarge the same type of fuel.

FIG. 3 also shows a perforated exhaust or discharge plate 20 on thebottom 3 of the housing as well as the exhaust plate 9 on top 2 of thehousing. This arrangement permits heat to bedirected in two directionsfrom the burner to fulfill the special heating requirements. Asmentioned above, the plates 9 and 20 may be omitted, if so desired.

FIG. 4 shows a modified form of the invention which may be mounted in aclosed-in area, such as a home furnace where secondary air may not beavailable, and where the secondary air to be drawn into the inlets 10can be introduced to the burner by controlled means. 6

A secondary air duct or housing 22 is provided around the periphery ofthe burner to enclose the secondary air inlets 10, as shown. The fuelinlet tube 5B is enlarged to embrace the secondary air duct and thisinlet tube carries the fuel nozzle 7 and ignition device 8. Thesecondary air duct is provided with fitting 23 to receive a connectionfrom an outside source of forced air, not shown, to supply secondary airto the air duct 22 to be drawn into the burner in the manner previouslydescribed. A damper 24, or other suitable air control device, may beused to control the amount of secondary air going into the duct 22.

FIG. 5 shows a modified form of the invention wherein two fuel intakes5C and 5D are employed, the inlets being relatively close to each other,as shown. The intake 5C is the primary fuel inlet and has an ignitiondevice 8, such as a pilot light, spark igniter or the like. This form ofthe invention is well suited to burner applications where high-fire andlow-fire conditions are called for. As can be readily seen, with onlythe primary fuel inlet in operation, a low-fire condition may bemaintained. When high-fire is called for, fuel may be injected intointake 5D and will be: ignited immediately and join with the burningfuel from intake 5C and a hotter burn will be obtained for as long asfuel is injected through intake 5D.

Although the burner structures shown and described are fed from nozzles7, it should be: recognized that it is intended to be within the scopeof this invention to utilize any of the burners shown as after burners,i.e. burners for recycling the burning the exhausts of other combustiondevices. In this instance, for example, the

burner structure of FIG. 2 may be used without nozzle It will beapparent to those skilled in the art that various changes andmodifications may be made to the apparatus shown and described hereinwithout departing from the spirit of the invention or from the scope ofth appended claims.

What I claimis: 1. A cyclonic burner comprising: a substantiallycircular housing having a top and a bottom, wall means joining said topand bottom and maintaining same in spaced substantially parallelrelationship and forming the periphery of said burner, said top havingan open area to act as a burner discharge, 1 l said wall means havingspaced secondary slotted air inlets arranged to extend between said topand bottom of said burner to inject air into said burner substantiallytangentially to the wall of said housing along its inside periphery,

' said secondary air inlets comprise lips extending in the direction ofcyclonic movement of the gases within said burner slightly past theslotted opening in the housing to create a pressure drop at said inletsto draw air into said burner and to prevent blow-back through saidinlets,

fuel inlet means connected to said housing and disposed to inject fuelinto said housing substantially tangentially to its inside wall,

and fuel ignition means within said burner adjacent said inlet meanswhereby the secondary air from said slotted air inlets and the primaryair and fuel from said fuel inlet swirl around the inside periphery ofsaid housing while burning to vaporize, distill and gasify the air andheavy fuel particles adjacent the inside wall of the said fuel inletmeans comprises a venturi section therein to aid in drawing air intosaid burner. 4. The cyclonic'burner set forth in claim 1 wherein:

the center portion of either the top or bottom of the housing isprovided with perforated sections for discharge of heated burner gasesfrom said burner.

5. The cyclonic burner set forth in claim 1 in further combination with:

a secondary air duct coaxially mounted around said housing and enclosingsaid secondary air inlets, and means to introduce air into saidsecondary air duct for injection through said secondary air inlets.

1. A cyclonic burner comprising: a substantially circular housing havinga top and a bottom, wall means joining said top and bottom andmaintaining same in spaced substantially parallel relationship andforming the periphery of said burner, said top having an open area toact as a burner discharge, said wall means having spaced secondaryslotted air inlets arranged to extend between said top and bottom ofsaid burner to inject air into said burner substantially tangentially tothe wall of said housing along its inside periphery, said secondary airinlets comprise lips extending in the direction of cyclonic movement ofthe gases within said burner slightly past the slotted opening in thehousing to create a pressure drop at said inlets to draw air into saidburner and to prevent blow-back through said inlets, fuel inlet meansconnected to said housing and disposed to inject fuel into said housingsubStantially tangentially to its inside wall, and fuel ignition meanswithin said burner adjacent said inlet means whereby the secondary airfrom said slotted air inlets and the primary air and fuel from said fuelinlet swirl around the inside periphery of said housing while burning tovaporize, distill and gasify the air and heavy fuel particles adjacentthe inside wall of the housing before being propelled inwardly of theburner for complete combustion.
 2. The cyclonic burner set forth inclaim 1 in further combination with: a second fuel inlet means connectedto said housing in spaced relationship to first said fuel inlet means tointroduce additional fuel to said burner tangentially to the inside wallof said burner.
 3. The cyclonic burner set forth in claim 1 wherein:said fuel inlet means comprises a venturi section therein to aid indrawing air into said burner.
 4. The cyclonic burner set forth in claim1 wherein: the center portion of either the top or bottom of the housingis provided with perforated sections for discharge of heated burnergases from said burner.
 5. The cyclonic burner set forth in claim 1 infurther combination with: a secondary air duct coaxially mounted aroundsaid housing and enclosing said secondary air inlets, and means tointroduce air into said secondary air duct for injection through saidsecondary air inlets.